Three Types of Contaminants
by Building Inspector and Indoor Air Specialist, Dan Schilling
© Copyright 2002 Residential Inspections LLC, All Rights Reserved
There are essentially three categories of indoor air contaminants found in virtually all homes:
1) PARTICLE POLLUTANTS
Indoor particle pollutants will typically consist of dirt, fibers from carpet, synthetic and natural fibers that shed from our clothing and seep out of clothes dryers, cellulose fibers from paper products such as paper towels, toilet paper and tissues, fiberglass, asbestos and cellulose fibers from home insulation, lead paint dust, chalk, dead skin cells sloughed off of human beings, pet dander, pet and human hair particles, insect parts, insect and rodent fecal particles, urine particles, mold spores and hyphal matter, dust mites, mite excrement, pollen, viruses and bacteria, grease particles from cooking, and carbon soot particles from fireplaces and candle burning.
Particle pollutants can be effectively reduced or eliminated with the following methods: a) manual cleaning, b) frequent vacuuming, c) collection in furnace filters, d) collection in single room air filters, e) directly settled out of the air through the replacement of natural levels of electrical ions to the indoor air. A combination of all of these methods is recommended.
2) CHEMICAL GASSES
Indoor off-gassing chemical pollutants typically include those coming from microbial volatile organic compounds, carpet, carpet under-matting, vinyl floor coverings, formaldehydes from construction adhesives, sub-flooring materials, man-made lumber products, man-made furniture and furniture components, paints, urethanes, plastic products, rubber items, magic marker fumes, hair spray, colognes, personal care products, cleaning products, air deodorizers, and dry cleaning chemicals used on clothing.
Off-gassing chemical odors can be effectively reduced or eliminated with the following methods: a) evacuation of the indoor air supply by opening windows and doors (very temporary.), b) collection of gasses with carbon filters (expensive and largely ineffective.), c) evacuated through exhaust fans (provided you have make-up air this is OK), d) evacuated through air-to-air exchangers (must be impeccably maintained or they can cause poisoning of your air), or e), oxidized through the replacement of natural levels of ozone into the indoor air (most efficient and economical, safe and natural).
Other gasses can include carbon monoxide, combustible gasses such as liquid propane and natural gas, radio active radon gas, and sewer gasses. These gasses respond to some of the above recommendations but will typically require a mechanical repair.
3) BIOLOGICAL POLLUTANTS
Indoor biological pollutants typically include mold, mildew, pollen, dust mites, mite excrement, pet dander, dead skin cells, pet and human hair particles, insect parts, insect and rodent fecal matter, urine particles, viruses and bacteria. These biological air pollutants can naturally increase in number or change in properties making them even more insidious.
Biological pollutants can be effectively reduced or eliminated through: a) control of indoor moisture levels, b) manual cleaning and occasionally chemical sanitizing, c) sanitation through oxidation with high levels of ozone in unoccupied rooms or spaces, e) controlled to safe outdoor levels through oxidation by maintaining natural ozone levels in indoor air. A combination of all of these methods is recommended.
Note: All of these pollutants mentioned above can be present in our air outdoors but are immediately and continuously cleansed from outdoor air to make it safe to breathe. This is not true indoors where pollutants can remain in the air for indefinite periods of time if specific strategies are not used to remove them.
Unfortunately, and purely by default, the primary method of contaminant removal in indoor environments is inhalation by humans and pets. With all of the illnesses now known to be caused from indoor air, this is obviously not a preferred method of air cleaning.
Due to the fact that indoor air contamination is typically caused from a variety of pollution sources, it will likely require a variety of the above solutions to remedy. If you will be using furnace or room air filters in your home to trap particles, you should understand that they only work on particles, and only on the larger particles. They do not work on chemical gasses or have no affect on non-airborne biological matter. If you will be using a natural air purification system in your home to combat these other air and surface pollutants, the air purifier should replace both the missing ions and ozone to similar levels as found outdoors and ideally should be rated to treat an average home with only one system required.
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